US 11,834,788 B2
Crescent former for producing tissue paper
Karl Adamsson, Karlstad (SE); Stefan Söderberg, Forshaga (SE); and Stefan Karlsson, Karlstad (SE)
Assigned to VALMET AB, Sundsvall (SE)
Appl. No. 18/006,589
Filed by VALMET AB, Sundsvall (SE)
PCT Filed Aug. 27, 2021, PCT No. PCT/EP2021/073695
§ 371(c)(1), (2) Date Jan. 24, 2023,
PCT Pub. No. WO2022/048993, PCT Pub. Date Mar. 10, 2022.
Claims priority of application No. 2051044-2 (SE), filed on Sep. 4, 2020.
Prior Publication US 2023/0212819 A1, Jul. 6, 2023
Int. Cl. D21F 1/32 (2006.01); D21F 9/00 (2006.01); D21F 1/02 (2006.01); D21F 3/04 (2006.01); D21F 3/08 (2006.01); D21F 5/18 (2006.01)
CPC D21F 1/32 (2013.01) [D21F 1/02 (2013.01); D21F 3/04 (2013.01); D21F 3/08 (2013.01); D21F 5/181 (2013.01); D21F 9/003 (2013.01)] 18 Claims
OG exemplary drawing
 
1. A crescent former for producing tissue paper, the crescent former comprising:
a forming section (A),
a press section (B), and
a drying section (C),
wherein the forming section (A) comprises:
a breast roll (13) and a forming roll (12),
a forming wire (14), and
a headbox (11) for injecting stock into a forming nip (15) formed between the breast roll (13) and forming roll (12),
wherein the press section (B) comprises a press roll (21)
wherein the drying section (C) comprises:
a Yankee roll (31) arranged to form a press nip (22) with the press roll (21) of the press section (B), wherein the press nip (22) is arranged in a positive machine (MD) direction from the forming nip (15),
wherein the crescent former further comprises a felt fabric (41) for carrying the stock from the forming nip (15) to the press nip (22), the felt fabric (41) being configured to receive stock from the headbox (11) and be pressed against the forming wire (14) in the forming nip (15), and the felt fabric (41) further being configured to be separated from the forming wire (14) after the forming nip (15) and to carry the stock to the press nip (22) where the stock is transferred to the Yankee roll (31),
wherein further the felt fabric (41) is configured to be returned from the press nip (22) to the forming nip (15) in a return section (D) such that the felt fabric (41) forms an endless loop,
wherein the return section (D) comprises a cleaning station (42),
wherein at least part of the cleaning station (42) being arranged in a negative machine direction (−MD) in relation to a center line (R) of the forming roll (12), said negative machine direction (−MD) being a direction that is opposite to the positive machine direction (MD), and
the felt fabric (41) is arranged to pass above the forming roll (12) on an upper level (66) of the former in the return section (D) when returning from the press nip (22) to the forming nip (15).